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Fix for #23

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- rewrote tessMeshMergeConvexFaces() to avoid infinite loops
This commit is contained in:
Mikko Mononen 2018-04-16 11:35:01 +03:00
parent 955761f46f
commit 1952b91b46
1 changed files with 39 additions and 41 deletions
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80
Source/mesh.c
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@ -699,54 +699,52 @@ static int CountFaceVerts( TESSface *f )
int tessMeshMergeConvexFaces( TESSmesh *mesh, int maxVertsPerFace )
{
TESSface *f;
TESShalfEdge *eCur, *eNext, *eSym;
TESSvertex *vStart;
int curNv, symNv;
TESShalfEdge *e, *eNext, *eSym;
TESShalfEdge *eHead = &mesh->eHead;
TESSvertex *va, *vb, *vc, *vd, *ve, *vf;
int leftNv, rightNv;
for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next )
for( e = eHead->next; e != eHead; e = eNext )
{
// Skip faces which are outside the result.
if( !f->inside )
eNext = e->next;
eSym = e->Sym;
if( !eSym )
continue;
// Both faces must be inside
if( !e->Lface || !e->Lface->inside )
continue;
if( !eSym->Lface || !eSym->Lface->inside )
continue;
eCur = f->anEdge;
vStart = eCur->Org;
while (1)
{
eNext = eCur->Lnext;
eSym = eCur->Sym;
leftNv = CountFaceVerts( e->Lface );
rightNv = CountFaceVerts( eSym->Lface );
if( (leftNv+rightNv-2) > maxVertsPerFace )
continue;
// Try to merge if the neighbour face is valid.
if( eSym && eSym->Lface && eSym->Lface->inside )
{
// Try to merge the neighbour faces if the resulting polygons
// does not exceed maximum number of vertices.
curNv = CountFaceVerts( f );
symNv = CountFaceVerts( eSym->Lface );
if( (curNv+symNv-2) <= maxVertsPerFace )
{
// Merge if the resulting poly is convex.
if( VertCCW( eCur->Lprev->Org, eCur->Org, eSym->Lnext->Lnext->Org ) &&
VertCCW( eSym->Lprev->Org, eSym->Org, eCur->Lnext->Lnext->Org ) )
{
eNext = eSym->Lnext;
if( !tessMeshDelete( mesh, eSym ) )
return 0;
eCur = 0;
}
}
}
if( eCur && eCur->Lnext->Org == vStart )
break;
// Continue to next edge.
eCur = eNext;
// Merge if the resulting poly is convex.
//
// vf--ve--vd
// ^|
// left e || right
// |v
// va--vb--vc
va = e->Lprev->Org;
vb = e->Org;
vc = e->Sym->Lnext->Dst;
vd = e->Sym->Lprev->Org;
ve = e->Sym->Org;
vf = e->Lnext->Dst;
if( VertCCW( va, vb, vc ) && VertCCW( vd, ve, vf ) ) {
if( e == eNext || e == eNext->Sym ) { eNext = eNext->next; }
if( !tessMeshDelete( mesh, e ) )
return 0;
}
}
return 1;
}